When it comes to research, no single method tells the whole story. Every approach has its strengths - and its blind spots. Triangulation is a strategy that helps researchers fill in those gaps by using multiple perspectives to explore the same research question. The result? A richer, more reliable understanding of complex issues.

What Is Triangulation?

In research, triangulation refers to the use of multiple methods, data sources, researchers, or theoretical frameworks to investigate one phenomenon. The goal is to cross-verify findings, to see whether different approaches lead to similar conclusions, and if they don’t, to explore why. Think of it like navigating a city you’ve never visited before. One map might show you the roads, another highlights walking paths, and a third points out landmarks. Each gives you useful information, but combining them makes you far more likely to find your way with confidence. Triangulation is often used in mixed methods research, where qualitative and quantitative approaches are combined, but it can also be applied within purely qualitative or purely quantitative designs by combining various methods.

Why Triangulation Matters

Triangulation is especially important in research involving human experience, behaviour, or perception - where reality is rarely straightforward. It helps strengthen research in three key ways:

1)       Enhancing validity: If different methods or sources converge on the same conclusion, it increases confidence in the result.

2)       Revealing complexity: When different perspectives produce different results, it can point to new layers of meaning or previously unrecognised factors.

3)       Reducing bias: Involving multiple people, approaches, or theories helps counteract individual or methodological blind spots.

Types of Triangulation

There’s more than one way to triangulate, but here are the most common forms:

·       Methodological Triangulation
Using different methods (e.g., interviews and surveys) to study the same issue. This is common in mixed methods research.

·       Data Triangulation
Gathering data from different times, settings, or participant groups. For example, surveying both teachers and students in an education study.

·       Investigator Triangulation
Involving multiple researchers in data collection or analysis to minimise individual bias or subjectivity.

·       Theory Triangulation
Applying different theoretical perspectives to interpret findings, helping you see the data through more than one lens.

Each type brings a different kind of insight and combining more than one can be especially powerful.

Triangulation in Action

Let’s think of a couple of scenarios of how triangulation might be used and why.

Imagine you’re researching the impact of a new mental health programme in schools. Quantitative data shows that anxiety scores dropped significantly after the intervention, but then you interview students and find that many didn’t enjoy or engage with the sessions. On their own, either result might feel incomplete. Together, they offer a more honest and helpful understanding: the programme may be effective, but it might need tweaking to improve the experience.

Or suppose you’re studying vaccine hesitancy. You could survey attitudes (quantitative), run focus groups (qualitative), compare findings across age groups (data triangulation), and bring in an external researcher to code the transcripts (investigator triangulation). With each layer, you further reinforce and challenge your interpretations.

A Mindset, Not Just a Method

Triangulation isn’t just a technical add-on - it reflects a research mindset. It’s about being curious, cautious, and committed to the depth and accuracy of information. Sometimes, triangulation confirms what you think. Other times, it surprises you. It helps build more trustworthy and nuanced research grounded in real-world complexity.

Whether you're using numbers, narratives, or both, triangulation reminds us that the truth is rarely one-dimensional, and the best insights often come from looking at the same story from more than one angle.

Lois Ann Parri

Originally written on March 2024 – London, England UK